Arylcarboxylic acid derivatives, in particular N-(1-cyanoalkyl)-2-phenoxypropionamide derivatives are useful for combatting phytopathogenic fungi and are described in CA 1,311,240.
In general, known processes to prepare the fungicidal N-(1-cyanoalkyl)-2-phenoxypropionamide derivatives such as that described in Research Disclosure 92306005 entail a non-aqueous system utilizing an organic amine base, such as a trialkylamine. However, on a manufacturing scale, use of irritants such as volatile organic amines leads to large quantities of effluent which require costly treatment and recovery steps. An alternate known process to prepare said propionamide derivatives is that described in Japanese patent application publication Kokai No. 5-9165 which utilizes 10% aqueous NaOH as the base. However, use of a strong base such as NaOH increases the rate of formation of undesired side-products such as the formation of the corresponding phenoxypropionic acid of the starting acid chloride. This unwanted by-product is not carried on to the desired amide product. Further, said acid by-product is a known herbicide derivative, and would, therefore, contaminate the desired fungicidal product with a phytotoxic compound. This contamination would be detrimental to the use of the product in crop production practice.
Therefore, it is an object of the present invention to provide an improved, economic and efficient process for the manufacture of N-(1-cyanoalkyl)-2-phenoxypropionamide derivatives. It is a feature of this invention that said propionamide derivatives are produced in higher yield and improved purity.
Other objects and features of the invention will become apparent from the detailed description set forth hereinbelow.